1. Field of the Invention
This invention relates generally to fluid dispensers, and more particularly to a fluid flow control valve for also preventing evaporative drying and thickening of the fluid and inadvertent fluid spillage or leakage from such fluid dispensers.
2. Description of Related Art
In dispensing light fluids from a squeezable fluid dispenser, many times more fluid than needed is inadvertently forced from the container or reservoir. This occurs because there is no convenient means for instantly arresting the flow of fluid from the applicator tip or cap attached to the container itself when inverted for dispensing fluid. Such an applicator tip may take the form of a brush, a grout roller, a spout, a nozzle and the like. Many prior art devices have attempted to resolve this problem of excess fluid dispensing and dripping, but they have either been too expensive or difficult to manufacture or failed to operate as intended.
U.S. Pat. No. 5,927,566 invented by Mueller discloses a one-piece dispensing system for a container and a method for making same. The dispensing valve includes an orifice. A dispensing structure with a lid containing a pressure-openable valve is disclosed in U.S. Pat. No. 6,089,419 invented by Gross. The lid includes a flexible valve with self-sealing slits which open to permit flow therethrough in response to pressure on the side of the valve.
Proshan, in U.S. Pat. No. 5,492,253, discloses a cap attachment having a flat disc with a socket adapted to receive the open end of the neck of a container. The disc has a slot centered therein and a vertical spout integral therewith.
U.S. Pat. No. 5,934,514 issued to Lampe, et al. teaches a dispensing valve closure which includes a self-sealing dispensing valve. An inner seal within the closure allows for sealing.
Lawrence, in U.S. Pat. No. 4,483,465, teaches a valve for dispensing fluids. The valve housing has a diaphragm disposed therein having at least one aperture for allowing passage of fluids. A one-piece check valve for use in an applicator tip for dispensing fluids is taught in U.S. Pat. No. 4,179,051 issued to Thomas. The valve comprises a reed and valve seat and a hinge section permitting the reed and valve seat to be folded over so that the reed portion seats on the seat provided by the valve seat portion. Fluid will pass through the check valve but any backflow is prevented by engagement of the reed on the shoulder portion.
Stull, in U.S. Pat. No. 5,071,017 discloses a valve-type closure with a resilient diaphragm containing a slit for the passage of fluids. The slit portion has abuttable, cooperative structures on one side which come into forcible abutment and open the slit as the slit portion bulges.
O'Neill discloses a squeeze container with a self-venting dispensing closure in U.S. Pat. No. 4,420,101. The container cap contains a flexible disc having an annular valve being shiftable to positions upstream and downstream of the valve seat responsive to pressure within the container.
U.S. Pat. No. 5,573,033 teaches a non-drip valve for discharging liquid having at least one elastic member which reduces its volume when the pressure of the fluid increases thereby freeing the through-flow channel.
A flexible vented self-sealing dispensing valve is taught by Fuchs in U.S. Pat. No. 6,062,436. The self-sealing closure assembly includes a dispensing valve of one-piece integrally molded elastic construction with a mouth portion that includes a slit opening oriented diametrically of the annular base.
Dunning teaches a squeeze container with a cap containing a tapered spout with an opening therethrough in U.S. Pat. No. 4,090,647. A closure cap is provided with a tongue to enhance the seal.
U.S. Pat. No. 5,839,626, issued to Gross, et al. teaches a closure having a dispensing valve with an orifice to permit liquid flow therethrough responsive to increased pressure within the container. An outer member on the base of the valve functions as a flow baffle for protecting the valve. A one-piece valve adapted for use in pressurized containers for either charging the container or dispensing the contents therefrom is shown in U.S. Pat. No. 3,586,068. This fluid pressure responsive valve is made as a single unitary piece with fluid passage means formed therein and a plug which is compressible to seal the passages when fluid pressure forces are imposed on the valve. Design Pat. D359,970, issued to Szabo, discloses a plug cap having a slit therethrough.
Applicant's prior U.S. Pat. No. 6,315,483 teaches a one-piece fluid check valve having structure cooperative with the tip of a squeezable fluid dispensing container which automatically self closes the instant that squeezing pressure against the sides of the resilient container is released. Moreover, the invention thereafter allows air to re-enter the container, which has been squeezed and distorted, to resiliently return to its normal configuration without fluid spillage. Applicant has, however, discerned a problem with this invention in that the very feature which allows re-entry of air into the container also results in inadvertent leakage of fluid from the dispenser when not in use and when fluid is placed against the fluid check valve because of container orientation.
In U.S. Pat. No. 5,551,599, Niss teaches a substantially more complex system for dispensing flowing substances from a container via a uniquely configured pump arrangement.
Another of applicant's prior U.S. Pat. No. 6,662,973, provides an improved fluid flow control valve of a squeezable fluid dispensing container which, aided by a bias spring, insures positive sealing of fluid within the container from advertent leakage while also regulating the flow of fluid when the container is squeezed in an inverted orientation. However, because of the delicate and sensitive nature of the seating ball arrangement, inconsistent spring biasing pressure thereagainst has been shown to be problematic in that the biasing pressure is sufficiently inconsistent to detract from overall product quality and consistent functionality.